Garuda - Garba Rujukan Digital

UTILIZATION OF MICRO SISAL FIBERS AS REINFORCEMENT AGENT AND POLYPROPYLENE OR POLYLACTIC ACID AS POLYMER MATRICES IN BIOCOMPOSITES MANUFACTURE Subyakto, Subyakto; Masruchin, Nanang; Prasetiyo, Kurnia Wiji; Ismadi, Ismadi
Indonesian Journal of Forestry Research Vol 10, No 1 (2013): Journal of Forestry Research
Publisher : Secretariat of Forestry Research and Development Agency

Show Abstract | Download Original | Original Source | Check in Google Scholar

Sisal (Agave sisalana) as a perennial tropical plant grows abundantly in Indonesia. Its fibers can be used as the reinforcement agent of biocomposite products. Utilization of sisal as natural fiber has some notable benefits compared to synthetic fibers, such as renewable, light in weight, and low in cost. Manufacture of biocomposite requires the use of matrix such as thermoplastic polymer, e.g. polypropylene (PP) and polylactic acid (PLA) to bond together with the reinforcement agent (e.g. sisal fibers). In relevant, experiment was conducted on biocomposites manufacture that comprised sisal fibers and PP as well as PLA. Sisal fibers were converted into pulp, then refined to micro-size fibrillated fibers such that their diameter reduced to about 10 Î¼m, and dried in an oven. The dry microfibrillated sisal pulp fibers cellulose (MSFC) were thoroughly mixed with either PP or PLA with varying ratios of MSFC/PP as well as MSFC/PLA, and then shaped into the mat (i.e. MSFC-PP and MSFC-PLA biocomposites). Two kinds of shaping was employed, i.e. hot-press molding and injection molding. In the hot-press molding, the ratio ofÂ MSFC/PP as well as MSFC/PLA ranged about 30/70-50/50. Meanwhile in the injection (employed only on assembling the MSFC-PLA biocomposite), the ratio of MSFC/PLA varied about 10/90-30/70. The resulting shaped MSFC-PP and MSFC-PLA biocomposites were then tested of its physical and mechanical properties. With the hot-press molding device, the physical and mechanical (strength) properties of MSFC-PLA biocomposite were higher than those ofÂ MSFC-PP biocomposite. The optimum ratio ofÂ MSFC/PP as well as MSFC/PLA reached concurrently at 40/60. The strengths of MSFC-PP as well as MSFC-PLA biocomposites were greater than those of individual polymer (PP and PLA). With the injection molding device, only the MSFC-PLAÂ biocompositeÂ was formedÂ and its strengthsÂ reachedÂ maximumÂ at 30/70Â ratio.Â The particular strengths (MOR and MOE) of MSFC-PLA biocomposite shaped with injection molding were lower than those with hot-press molding, both at 30/70 ratio. The overall MOR of such MSFC- PLA biocomposite was lower than that of pure PLA, while its MOE was still mostly higher.

Bacteria as Self-Healing Agent in Mortar Cracks Nugroho, Ananto; Satyarno, Iman; Subyakto, Subyakto
Journal of Engineering and Technological Sciences Vol 47, No 3 (2015)
Publisher : ITB Journal Publisher, LPPM ITB

This study was aimed at finding the possibility to apply Bacillus subtilis integrated into mortar matrix to act as a self-healing agent to seal cracks. Bacterial spores at concentrations of 104, 105, and 106 cells/ml were directly added into pulverized fly ash as medium to protect bacteria in high alkaline conditions. The results show that the addition of Bacillus subtilis spores into the mortar mixture enhanced the compressive strength, especially at a cell concentration of 105 cells/ml. The bacterial mortar had a small ability to recover the stiffness of the mortar, amounting to 34.85% of its original stiffness. The effectiveness of crack sealant and resistance to water flow were limited to a maximum crack width size of 0.22 mm. Physical observation showed that the bacterial mortar is characterized by calcite precipitation as a product of ureolytic bacteria. The quantity and distribution of calcite precipitate depended on the precipitation weight, gravity direction and oxygen availability. Meanwhile, chemical analysis using XRD and EDX showed that the bacterial mortar had a better crystallinity.

UTILIZATION OF MICRO SISAL FIBERS AS REINFORCEMENT AGENT AND POLYPROPYLENE OR POLYLACTIC ACID AS POLYMER MATRICES IN BIOCOMPOSITES MANUFACTURE Subyakto, Subyakto; Masruchin, Nanang; Prasetiyo, Kurnia Wiji; Ismadi, Ismadi
Indonesian Journal of Forestry Research Vol 10, No 1 (2013): Journal of Forestry Research
Publisher : Secretariat of Forestry Research and Development Agency

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20886/ijfr.2013.10.1.11-20

Sisal (Agave sisalana) as a perennial tropical plant grows abundantly in Indonesia. Its fibers can be used as the reinforcement agent of biocomposite products. Utilization of sisal as natural fiber has some notable benefits compared to synthetic fibers, such as renewable, light in weight, and low in cost. Manufacture of biocomposite requires the use of matrix such as thermoplastic polymer, e.g. polypropylene (PP) and polylactic acid (PLA) to bond together with the reinforcement agent (e.g. sisal fibers). In relevant, experiment was conducted on biocomposites manufacture that comprised sisal fibers and PP as well as PLA. Sisal fibers were converted into pulp, then refined to micro-size fibrillated fibers such that their diameter reduced to about 10 Î¼m, and dried in an oven. The dry microfibrillated sisal pulp fibers cellulose (MSFC) were thoroughly mixed with either PP or PLA with varying ratios of MSFC/PP as well as MSFC/PLA, and then shaped into the mat (i.e. MSFC-PP and MSFC-PLA biocomposites). Two kinds of shaping was employed, i.e. hot-press molding and injection molding. In the hot-press molding, the ratio ofÂ MSFC/PP as well as MSFC/PLA ranged about 30/70-50/50. Meanwhile in the injection (employed only on assembling the MSFC-PLA biocomposite), the ratio of MSFC/PLA varied about 10/90-30/70. The resulting shaped MSFC-PP and MSFC-PLA biocomposites were then tested of its physical and mechanical properties. With the hot-press molding device, the physical and mechanical (strength) properties of MSFC-PLA biocomposite were higher than those ofÂ MSFC-PP biocomposite. The optimum ratio ofÂ MSFC/PP as well as MSFC/PLA reached concurrently at 40/60. The strengths of MSFC-PP as well as MSFC-PLA biocomposites were greater than those of individual polymer (PP and PLA). With the injection molding device, only the MSFC-PLAÂ biocompositeÂ was formedÂ and its strengthsÂ reachedÂ maximumÂ at 30/70Â ratio.Â The particular strengths (MOR and MOE) of MSFC-PLA biocomposite shaped with injection molding were lower than those with hot-press molding, both at 30/70 ratio. The overall MOR of such MSFC- PLA biocomposite was lower than that of pure PLA, while its MOE was still mostly higher.

Physical-Mechanical Properties and Bonding Mechanism of Corn Stalks Particleboard with Citric Acid Adhesive Prasetiyo, Kurnia Wiji; Oktaviani, Linda; Astari, Lilik; Syamani, Firda A; Subyakto, Subyakto; Achmadi, Suminar S
Jurnal Ilmu dan Teknologi Kayu Tropis Vol 16, No 2 (2018): Jurnal Ilmu dan Teknologi Kayu Tropis
Publisher : Jurnal Ilmu dan Teknologi Kayu Tropis

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (38.454 KB)

As a natural fiber and agricultural by-product, corn stalks (Zea mays saccharata) is considered as an alternative raw material to produce particleboard. Corn stalks is a good source of lignocelluloses, renewable and low cost. This research was aimed to investigate the characteristics of corn stalk particleboard with citric acid as adhesive. This study also evaluated bonding mechanism particle with citric acid and the bonds between celluloses derived corn stalk with citric acid. The boards were manufactured under the hot pressing temperature 200 oC for 10 min. The citric acid concentration was varied in 0, 15, 20 and 25 wt%. The board size and target density were (25 x 25 x 0.9) mm3 and 0.8 g.cm-3. Results showed that the physical properties of particleboards improved with increasing citric acid concentration up to 20 wt%. At the optimum citric acid content of 20 wt% could provide particleboards with the modulus of rupture, modulus of elasticity and internal bonding satisfied the requirement of the 13 type of the JIS A 5908 (2003) standard. Infrared (IR) spectral analysis from board which manufactured from isolated cellulose was mixed citric acid and pressed on temperature 200 oC showed the presence of ester linkages that the carboxyl and hydroxyl groups of citric acid had reacted with the hydroxyl groups of corn stalk cellulose.Keywords : citric acid, corn stalk, concentration, particleboard, adhesive

Characteristics of Environmentally Friendly Food Container Composite Made From Sorghum Bagasse and Citric Acid ismadi, ismadi; Kusumah, Sukma Surya; Subyakto, Subyakto; Subiyanto, Bambang; Suryanegara, Lisman; Marlina, Resti
Jurnal Bahan Alam Terbarukan Vol 9, No 2 (2020): December 2020 [Nationally Accredited - Sinta 2]
Publisher : Universitas Negeri Semarang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.15294/jbat.v9i02.27345

The common food container product was made from plastic such as polypropylene, polystyrene, etc which has slowed to degrade hence affected to the environmental pollution and health disorder. Therefore, environmentally friendly food container composite is developed from sustainable resources such as sorghum bagasse and citric acid. The effects of sorghum species, sorghum particles and citric acid content on the composite properties were investigated. Local species of sorghum was used as raw material such as Super 2 in the manufacturing of food packaging.Ã‚Â The size and moisture content of the particles were passthrough on 40 mesh and 10%, respectively. The content of the particle was variated such as 10, 15, and 20% wt. Furthermore, citric acid was used as a binder with difference content such as 10, 20, and 30% wt.Ã‚Â Those raw materials were mixed with tapioca starch, polyvinyl alcohol (PVA), and glutaraldehyde. The mixing material was hot pressed at 180 Ã¢â€žÆ’ for 15 minutes. The composite dimension was 12 cm x 10 cm x 3 mm. The physical and mechanical properties of the composite were carried out. Considering the properties of the composite, sorghum bagasse and citric acid are suitable as raw material of food container composite.

Hybrid Particleboard Made of Corn Husk (Zea Mays L.) and Sembilang Bamboo (Dendrocalamus Giganteus Munro): Effect of Adhesive Type and Particle Composition Prasetiyo, Kurnia Wiji; Hermawan, Dede; Hadi, Yusuf Sudo; Subyakto, Subyakto; Firdaus, Muhammad; Syamani, Firda Aulya; Astari, Lilik
Jurnal Bahan Alam Terbarukan Vol 10, No 2 (2021): December 2021 [Nationally Accredited - Sinta 2]
Publisher : Universitas Negeri Semarang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.15294/jbat.v10i2.31600

Particleboard is a panel product made of wood particles or other lignocellulosic materials added with adhesive then pressed. The development of particleboard manufactured using non wood biomass has become important due to the decreased of wood as main raw material for the particleboard industry. Corn husk (Zea mays L.) and Sembilang bamboo (Dendrocalamus giganteus Munro) are lignocellulosic biomass that has potential as renewable materials for hybrid particleboard. The purposes of this study were to determine the suitability, the effect of adhesive type, and particle composition on physical and mechanical properties of hybrid particleboard made of corn husk and Sembilang bamboo particles. The adhesive types used were urea formaldehyde (UF) and phenol formaldehyde (PF) with 10 wt% adhesive content and the composition of corn husk : Sembilang bamboo was set at 100 : 0, 75 : 25, 50 : 50, 25 : 75, 0 : 100 (% w/w). The target density of hybrid particleboard was set at 0.80 g/cm3. The boards were manufactured at 130 °C for UF and 150 °C for PF press temperature, 10 minutes and 2.5 MPa for the pressure of the hot press. The results showed that hybrid particleboard properties improved with increasing the amount of Sembilang bamboo particles in the board. Hybrid particleboard properties affected in ascending order were modulus of rupture (MOR), modulus of elasticity (MOE), internal bond (IB) and screw holding power (SHP). Generally, hybrid particleboard bonded PF adhesive has better properties than bonded UF adhesive. Results indicated that the addition of Sembilang bamboo particles in the mixture resulted in better properties of hybrid particleboard.

Synthesis and Characterization of Activated Carbon from Lignocellulosic Biomass: Oil Palm Empty Fruit Bunches and Mahogany Sawdust Arundina, Ria Yolanda; Permana, Indri; Togatorop, Ester Rimma Suryani; Ismadi, Ismadi; Kusumah, Sukma Surya; Budiman, Ismail; Subyakto, Subyakto; Marlina, Resti
Jurnal Bahan Alam Terbarukan Vol 10, No 2 (2021): December 2021 [Nationally Accredited - Sinta 2]
Publisher : Universitas Negeri Semarang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.15294/jbat.v10i2.33488

Lignocellulosic biomass is a biological residue from the agricultural or forestry industry which is composed of polymeric cellulose, hemicellulose, lignin, and other extractive components. One of the products in the utilization of lignocellulosic biomass waste is activated carbon products. In this study, two types of lignocellulosic biomass waste were used, namely Empty Palm Oil Bunches (OPEFB) and Mahogany Sawdust (MS) to be converted into activated carbon using the hydrothermal-pyrolysis method. Potassium hydroxide (KOH) was used as an activating agent at high concentrations (50% w/w) to improve the adsorption mechanism in activated carbon material. Proximate analysis was carried out to obtain information related to yield, moisture content, and ash content. In addition, activated carbon samples were characterized using FTIR, XRD, and FESEM to observe the chemical bonds, structure, and morphology of activated carbon, respectively. The proximate analysis showed that the activated carbon sample had met the SNI 63-3730-1995 standard for technical activated carbon on the parameters of water content and ash content, while the FTIR spectrum showed the mechanism of biomass conversion from raw materials to activated carbon on a chemical bond approach. Furthermore, the XRD graph shows a reduction in the crystal size of the material from raw material to activated carbon material. Finally, the FESEM image shows a significant increase in the quality and quantity of pores on the carbon material before and after activation.

The investigation of the properties of filaments fabricated from carbon biomass and LLDPE Pramono, Agus Edy; Patrick, Yohannes; Zuhri, Aminudin; Setiyadi, Iman; Maksum, Ahmad; Indayaningsih, Nanik; Subyakto, Subyakto
Jurnal Polimesin Vol 22, No 4 (2024): August
Publisher : Politeknik Negeri Lhokseumawe

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30811/jpl.v22i4.5084

This study aims to develop composites using electrically conductive carbon and polymer polyethylene (LLDPE) to enhance electrical conductivity. Investigations have been conducted on the fabrication of electrically conductive composites and the modulus of elasticity through heat compaction using mixtures of carbon-LLDPE powders. Heat compaction is performed at temperatures ranging from 120°C to 150°C, with varying composition ratios of carbon-LLDPE, including 50:50, 60:40, and 70:30 % wt. Higher proportions of carbon and compaction temperatures are correlated with increased electrical conductivity. For instance, the C7-3LLDPE composite, compacted at 150°C, demonstrates the highest electrical current flow of 0.0018 A, whereas the C5-5LLDPE composite, compacted at 135°C, exhibits the lowest current flow at 0.0000638 A. Regarding the modulus of elasticity, the composition ratio of C7-3LLDPE, compacted at 120°C, achieves the highest value at 2686.43 [N/mm2 ]. Conversely, the composition ratio of C5-5LLDPE, compacted at 135°C, yields the lowest modulus of elasticity at 1530.94 [N/mm2 ]. Elasticity modulus testing follows the ASTM D638 standard, with a speed of 2 mm/min. It is observed that increasing the compaction temperature results in a decreased modulus of elasticity across all composition ratios. Furthermore, a higher carbon content within the composite corresponds to a higher modulus of elasticity, regardless of the compaction temperature.

The Urgency of Pancasila Values in the Implementation of Humane Public Policy in the Environmental Sector Subyakto, Subyakto
Pena Justisia: Media Komunikasi dan Kajian Hukum Vol. 20 No. 1 (2021): Pena Justisia
Publisher : Faculty of Law, Universitas Pekalongan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31941/pj.v20i1.3390

Developments in the industrial world have resulted in a paradigm shift in environmental management, resulting in environmental policies leaving far from ecological identity in every product produced. This article using the juridical empiricism method aims to discuss the urgency of Pancasila values in the implementation of humanist public policies in the environmental sector. Based on the studies conducted, it is known that changes in the world order due to technological and cultural advances have resulted in the degradation of the human paradigm in terms of environmental management. The degradation of this environmental management paradigm has left far the aspects of ecological needs for the environment. In short, this can be said to have released the human dimension in viewing the use of the environment which is obsessed with industrial profits alone. Pancasila through its balance teaching mandates that legal policies related to environmental management return to its soul, namely ecological awareness. The position of Pancasila is important because every value contained in the Five Pancasila Precepts is basically an accumulation of values of equality and values of balance. Operationally the values of Pancasila require recognition and protection for physical and spiritual needs related to the dimensions of social life as well as the human dimension as individuals, especially in terms of environmental policy issues.

UTILIZATION OF CITRIC ACID AS BONDING AGENT IN SEMBILANG BAMBOO (Dendrocalamus giganteus Munro) PARTICLEBOARD PRODUCTION A. Syamani, Firda; Z. Arifqi, Agus; S. Munawar, Sasa; Sudarmanto, Sudarmanto; Astari, Lilik; W. Prasetiyo, Kurnia; Gopar, Mohamad; Ismadi, Ismadi; S. Kusumah, Sukma; H. Hussin, Mohd.; Subyakto, Subyakto; S. Hadi, Yusuf; Umemura, Kenji
Indonesian Journal of Forestry Research Vol. 9 No. 1 (2022): Indonesian Journal of Forestry Research
Publisher : Association of Indonesian Forestry and Environment Researchers and Technicians

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.59465/ijfr.2022.9.1.99-120

Citric acid was utilized as a bonding agent in the production of Sembilang bamboo particleboard. The limitation in using bamboo for particleboard production is that the silica content in bamboo skin can accelerate particleboard processing machines' bluntness and reduce particle adherence in particleboard manufacturing. This research aimed to investigate the influence of bamboo skin and citric acid content on the characteristics of Sembilang bamboo particleboard. Particleboards were prepared using bamboo particles (type A) and unskinned bamboo particles (type B). The citric acid solution (59%) was sprayed over the surface of bamboo particles to obtain three different levels of citric acid, i.e., 15, 20, and 25 % (based on bamboo particles’ dry weight). The Sembilang bamboo particleboards were manufactured using a hot-pressing machine at 200°C, 5 MPa for 10 min. The particleboard targeted density was 0.8 g/cm3. The type B particleboards’ internal bond (IB), modulus of rupture (MOR), water absorption (WA), and thickness swelling (TS) were superior compared to the type A particleboards. This was influenced by the lower concentration of silica in type B particleboards, which tend to allow an intimate contact area among particles and citric acid then produced better quality particleboards compared to type A particleboards. The type B particleboards met the obligation of JIS A 5908 for type 18 particleboard in terms of modulus of rupture, modulus of elasticity, and internal bond, however, only fulfilled the type 8 particleboard in terms of screw holding power.

Title

Found 10 Documents
Search

Abstract

Abstract

Abstract

Abstract

Abstract

Abstract

Abstract

Abstract

Abstract

Abstract

Title Search

Found 10 Documents Search

Abstract

Abstract

Abstract

Abstract

Abstract

Abstract

Abstract

Abstract

Abstract

Abstract

Title

Found 10 Documents
Search